The present invention relates to a tool holder and more particularly to a rotatable tool holding turret of the type adapted for use with a lathe or the like.
Tool turrets of the foregoing type generally include a base which is suitably located and attached to the lathe way. A turret head having a plurality of radially extending and angularly spaced tools mounted therein is supported on the base. The turret head is mounted for turning on the base in an unclamped or unclutched position to a clamped or clutched position in which a selective one of the tools is located in an operative work performing position. Such movement may be automatically accomplished by means of a numerical control system.
By the present invention it is proposed to provide a tool holding turret of the foregoing type having an improved arrangement for turning and clamping the turret head to the different work performing positions.
This is accomplished by a tool holding turret comprising generally a base having a clutch surface and a hydraulic chamber. A turret head is mounted on the base and is formed with a clutch surface complementary to the base clutch surface. A piston means is attached to the turret head and has a piston head slidably disposed in the hydraulic chamber so that upon the controlled introduction of hydraulic fluid therein, the head is moved between a clutched and unclutched position. The ports through which the fluid flows into and out of the chamber are located so that the piston head serves as a hydrostatic and hydrodynamic bearing in the unclamped position thereof. A hydraulically actuated mechanical means is provided for rotating the head relative to the base when the head is in the unclamped position thereby to selectively position one of the tools carried by the turret head into a work performing position.
To permit the replacement of different tools, the head is formed with a separable tool holding section and clutch surface sections are maintained in alignment by aligning pins. A rubber bushed pin absorbs the energy imposed on the turret internal mechanism when the head and tools are stopping and starting when selectively positioning one of the tools carried by the turret head into a work performing position.
As a further feature of the present invention the clutching surfaces are formed as precision ground serated teeth of substantially rectangular cross section. The clutching surfaces are protected by overlapping skirt means disposed radially outwardly of the surfaces thereby to provide in the nature of a labyrinth seal in both the clutched and unclutched positions of the turret head.
Further features of the invention will hereinafter appear.